Time schedule controller and parts and system therefor

ABSTRACT

A time schedule controller wherein the high limit index and the set point index respectively have members movable therewith and alignable in relation to each other only when the set point index reaches the setting of the high limit index. An actuator for terminating the operation of the set point index in the rate of rise thereof is only actuated when the alignable members of the high limit index and the set point index that are operatively associated therewith are in their aligned relation thereof.

United States Patent Hardin [451 May 1, 1973 173 Assignee: Robertshaw[54] TIME SCHEDULE CONTROLLER AND PARTS AND SYSTEM THEREFOR [75]inventor: George T. Hardin, Knoxville, Tenn.

Controls Company, Richmond, Va.

[22] Filed: Oct. 8, 1971 [21] Appl.No.: 187,641

[52] US. Cl ..236/46, 236/18 [51] Int. Cl ..G05b 19/04, GOSb 11/50 [58]Field of Search ........236/46;-219/492 [56'] References Cited UNITEDSTATES PATENTS 2,319,114 5/1943 Cook ..236/46 2,347,344 4/1944 Waidelich.;...236/46 X Primary Examiner-William E. Wayner Att0rneyAuzvilleJackson, Jr. et al.

[57] ABSTRACT A time schedule cont-roller wherein the high limit indexand the set point index respectively have members movable therewith andalignable in relation to each other only when the set point indexreaches the setting of the high limit index. An actuator for terminatingthe operation of the set point index in the rate of rise thereof is onlyactuated when the alignable members of the high limit index and the setpoint index that are operatively associated therewith are in theiraligned relation thereof.

10 Claims, 15 Drawing Figures PATEPHEDVAY H975 v SHEET 3 OF 4 FBGHFIG.!0

FiG.l2 75 TIME SCHEDULE CONTROLLER AND PARTS AND SYSTEM THEREFORBACKGROUND OF THE INVENTION Time schedule controllers have been providedwherein each controller is adapted to be set for an initial startingcondition of and for a controlled rate of rise of a set point indexthereof so that a controlled device, such as a heat exchanger, will havethe output effect thereof controlled at the rate of rise of the setpoint index thereof until the set point index reaches a set high limitindex point at which time the controller will automatically cause theoutput effect of the controlled device to remain at the high limitthereof for a period of time as set by a hold timer of the controllerfollowed by an automatic shutdown of the operation of the controlleddevice at the end of the predetermined hold period of the controller.Various means have been provided in such time schedule controllers toaccomplish these automatic functions.

SUMMARY This invention provides an improved time schedule controller ofthe above-described type having improved means for controlling themanual or automatic sequence of operation thereof.

This invention also provides an improved time schedule controlled systemas well as improved parts for such a time schedule controller or thelike.

In particular, one embodiment of the time schedule controller of thisinvention, wherein a high limit index is adapted to be set at a desiredcondition and the rate of rise of the set point index is adapted to beselected so that the controller will tend to maintain an output effectof a controlled device at the selected rate of rise of the set pointindex until the output effect reaches the set condition of the highlimit index, comprises means movable with the high limit index and theset end point index and alignable in relation to each other only whenthe set point index reaches the setting of the set high limit index.Actuator means are provided for terminating the operation of the setpoint index in the rate of rise thereof when the actuator means isactuated, the alignable means of the high limit index and the set pointindex being operatively associated with the actuator means to actuatethe same only when the alignable means are in the aligned relationthereof. In the embodiment of the time schedule controller of thisinvention, the alignable means of the set point index comprises arotatable cam member movable in unison with the set point index and thealignable means of the high limit of the set high limit index comprisesan electric switch movable with the high limit index so that the cammember of the set point index will only actuate the electric switch whenthe same is aligned with the electric switch, as will be apparenthereinafter.

The time schedule controller of this invention also has improved meansfor setting the indexes thereof in the desired initial set positionsthereof.

Accordingly, one of the objects of this invention is to provide animproved time schedule controller having one or more of the novelfeatures set forth above or herein-after shown or described.

Another object of this invention is to provide an improved time schedulecontrolled system utilizing such a time schedule controller or the like.

Another object of this invention is to provide improved parts for such atime schedule controller or the like.

Other objects, uses and advantages of this invention are apparent from areading of this description, which proceeds with reference to theaccompanying drawings forming a part thereof and wherein DESCRIPTION OFTHE DRAWINGS FIG. 1 is a front view of the time schedule controller ofthis invention.

FIG. 2 is a view similar to FIG. 1, with the front cover of the timeschedule controller in an open position thereof and with certain partsinside the time schedule controller being broken away.

FIG. 3 is an enlarged, fragmentary view of the bridge and pen assemblyof the controller of FIG. 1.

FIG. 4 is a side view of the bridge and pen assembly of FIG. 3.

FIG. 4A is an enlarged fragmentary cross-sectional view takensubstantially on line 4A-4A of FIG. 3.

FIG. 5 is a fragmentary, cross-sectional view taken on line 5-5 of FIG.4.

' FIG. 6 is a fragmentary, cross-sectional view taken on line 6-6 ofFIG. 4.

FIG. 7 is a fragmentary, cross-sectional view taken on line 7-7 of FIG.4.

FIG. 8 is an end view of the bridge and pen assembly of FIG. 3.

FIG. 9 is an enlarged, fragmentary, cross-sectional view taken on line99 of FIG. 1 and illustrating the index adjusting means of the timeschedule controller of this invention.

FIG. 10 is a fragmentary, perspective view illustrating the operation ofthe adjustment means of FIG. 9, with the adjustment means being in oneposition thereof.

FIG. 11 is a view similar to FIG. 10 and illustrates the adjustmentmeans being in another position thereof.

FIG. 12 is a fragmentary, cross-sectional view illustrating a solenoidoperated valve means for the control system of the time schedulecontroller of this invention.

FIG. 13 is a schematic view illustrating the control system that isoperated by the time schedule controller of this invention.

FIG. 14 is a schematicview illustrating the electrical circuit for thetime schedule controller of this inventlon.

DESCRIPTION OF ILLUSTRATED EMBODIMENT While the various features of thisinvention are hereinafter described and illustrated as beingparticularly adapted to control the output temperature effect of a heatexchanger means, it is to be understood that the various features ofthis invention can be utilized singly or in any combination thereof toprovide a time schedule control for other types of systems as desired.

Also, it is to be understood that the various parts of the time schedulecontroller of this invention can be utilized in other types of controlinstruments or devices, if desired.

Therefore, this invention is not to be limited to only the embodimentillustrated in the drawings, because the drawings are merely utilized toillustrate one of the wide variety of uses of this invention.

Referring now to FIGS. 1, 2 and 13, the time schedule controller of thisinvention is generally indicated by the reference numeral and isutilized to control the output temperature effect of a heat exchanger21, FIG. 13, forming part of the controlled system of this inventionthat is generally indicated by the reference numeral 22 in FIG. 13.

The controlled system 22 includes a main steam valve 23 having a valveseat 24 for interconnecting a source of steam 25 to a conduit 26 leadingto the heating coil of the heat exchanger 21, the valve seat 24 beingopened and closed by a valve member 25 being positioned relative to thevalve seat 24 by a pneumatically operated actuator 26 in a manner wellknown in the art whereby an increase of pneumatic pressure in thechamber 27 of the pneumatically operated actuator 26 will cause thevalve member 25 to be moved further away from the valve seat 24 to admitmore steam to the heat exchanger 21 and, conversely, a decrease in thepneumatic pressure in the chamber 27 of the actuator 26 will cause thevalve member 25 to be moved closer to the valve seat 24 under the forceof a compression spring 28 to decrease the amount of steam beingdirected to the heat exchanger 21. Thus, the output temperature effectof the heat exchanger 21 increases as the valve member 25 moves fartheraway from the valve seat 24 and decreases as the valve member 25 movestoward the valve seat 24.

While the particular process being heated by the heat exchanger 21 canvary, the heat exchanger 21 in FIG. 13 is illustrated as heating a dyebath 21' for dyeing textiles and the like.

As illustrated in FIG. 13, the controller 20 for the system 22 includesa balance beam 29 ofa proportional mechanism 30 that is well known inthe art and is therefore schematically illustrated in FIG. 13 as havinga vent opening device or nozzle 31 for a conduit 32 that is adapted tobe supplied fluid pressure from an external source 33 and has arestrictor 34 therein. The balance beam 29 is positioned relative to thevent or nozzle opening 31 by a process bellows construction 35 and afeedback bellows construction 36 respectively interconnected to opposedends 37 and 38 of the balance beam 29. The process bellows 35 has thefluid in the chamber 39 thereof adapted to be expanded and contracted inrelation to the sensing of the output temperature effect of the heatexchanger 21 by the sensing bulb 40 disposed in the process bath 21.Thus, should the output temperature effect of the heat exchanger 21exceed the particular output temperature effect setting of the processbellows 35, the resulting expansion of the fluid in the chamber 39causes the balance beam 29 to move away from the vent opening 31 acertain amount to vent a greater portion of the fluid pressure in theline 32 than before and, thus, causes a venting of some of the fluidpressure in the chamber 27 of the pneumatic actuator 26 for the valvemeans 23 in a manner more particularly hereinafter described so as tomove the valve member 25 closer to the valve seat 24 and therebydecrease the amount of steam being directed to the heat exchanger 21 totend to maintain the output temperature effect thereof to the level asset by the bellows construction 35. Conversely, should the outputtemperature effect of the heat exchanger 21 fall below the settemperature of the process bellows 35, the fluid in the chamber 39contracts so as to move the beam 29 closer to the vent opening 31 andincrease the pressure of fluid in the conduit 32 and, thus, increasesthe pressure of the fluid in the chamber 27 of the pneumatic actuator 26so as to move the valve member 25 farther away from the valve seat 24and thereby permit an increased flow of steam through the heat exchanger21 to increase the output temperature effect thereof.

Thus, the positioning of the balance beam 29 relative to the ventopening 31 tends to maintain the output temperature effect of the heatexchanger 21 at the output temperature effect setting for the processbellows 35.

Such proportional mechanism 30 can be seen inside the casing 41 of thecontroller 20 in FIG. 2 where the cover 42 of the controller 20 has beenmoved to the open position and, in a manner well known in the art, thetemperature setting of the process bellows 35 and/or proportionalmechanism 30 is under the control of a set point index link 43 that isadapted to automatically change the temperature setting of theproportional mechanism 30 upon movement of the set point index link 43to change the output temperature effect of the heat exchanger 21 that isbeing controlled by the proportional mechanism 30 in a mannerhereinafter described. Also, the process bellows construction 35 and/orproportional mt. fianism 30 is adapted to position a process pen link 44of the controller 20 in relation to the actual output temperature effectof the heat exchanger 21 as being sensed by the bulb 40 even though theoutput temperature of the heat exchanger 21 may be at that particulartime different than the intended setting thereof by the particularposition of the set point index link 43.

In general, the controller 20 of this invention includes a bridge andpen assembly 45 which has an ink pen arm 46 positioned by the processpen link 44 so as to record on a rotatably driven chart 46 of thecontroller 20 the actual output temperature effect of the heat exchanger21 in the process bath 21 before, during and after the operation of theheat exchanger 21. The pen and bridge assembly 45 also includes a highlimit index or pointer 47 which is adapted to be set at a desired highlimit temperature setting that the output temperature effect of the heatexchanger 21 is to reach by a selector knob 48 on the cover 42 of thecasing 41 in a manner hereinafter described so that when the outputtemperature effect of the heat exchanger 21 reaches the outputtemperature setting of the high limit index 47, the controller 20, in amanner hereinafter described, will hold such output temperature effectfor a predetermined length of time as set by a hold timer adjustmentknob 49 that controls the setting of a hold timer motor 50 that isillustrated in FIG. 2 as well as in the electrical circuit 51 for thecontroller 20 in FIG. 14.

The bridge and pen assembly 45 includes a set point index or pointer 52which is adapted to be set at a desired starting output temperatureeffect for a time schedule control of the system 22 by the controller 20by an adjusting knob 53 on the cover 42 of the controller 20 in a mannerhereinafter described, such setting of the set point index 52 settingthe position set point index link 43 to initially set the proportionalmechanism 30 to tend to maintain the output temperature effect of theheat exchanger 21, when the system 22 is subsequently set intooperation, at the initial output temperature effect setting of the index52.

A rate of rise adjustment knob 54 on the cover 42 of the controller isadapted to be set at a desired rate of rise of temperature so that oncethe set starting temperature effect of the heat exchanger 21 has beenreached, the index 52 will cause the output temperature effect of theheat exchanger 21 to continuously rise at the set rate of the knob 54until the output temperature effect of the heat exchanger 21 reaches thehigh limit output temperature effect setting of the index 47. When thehigh limit output temperature effect is reached, the same will then beheld by the controller 20 for the length of time set on the hold timer50 by the knob 49. The rate of rise adjusting knob 54 of the controller20 sets the rate of rise timer motor 55 of the circuit 51 at the desiredrate of rise setting thereof for the previously described purpose.

The cover 42 of the controller 20 includes a manually operated,electrical power on-off switch button 56 which controls a pair ofswitches 57 and 58 in the circuit 51 and respectively disposed in thefused power source lines L and L so that when the button 56 is moved toan on position thereof, the switches 57 and 58 respectively close andinterconnect the fused power source lines L and L to leads 59 and 60.However, when the button 56 is moved to the off position thereof, thesame opens the switches 57 and 58 to respectively disconnect the powersource lines L and L from the leads 59 and 60.

A start cycle button 61 is provided on the cover 42 of the controller 20and, when pushed to start a particular cycle of operation in the mannerhereinafter described, will cause the hold timer 50 of the circuit 51 tolatch the normally closed relay contacts 50 in an open position thereofwhile latching the normally open relay contacts 50" in a closedcondition thereof.

A selector switch 63 and an electro-pneumatic (E/P) valve 64 arecombined in one assembly 65 inside the casing 41 of the controller 20 asillustrated in FIG. 2 with the selector switch 63 being illustrated inthe circuit 51 of FIG. 14 as being movable from the automatic settingposition thereof illustrated in FIG. 14 against a contact 66 to a manualposition thereof against a contact 67 for a purpose hereinafterdescribed. However, when the selector switch 63 is moved to theautomatic position illustrated in FIG. 14, an operator can control thesystem 22 by the controller 20 by merely setting the high limit index 47by the knob 48 to the temperature at which the set point index 52 is tostop at the end of its travel and the set point index 52 is thenpositioned to the desired initial temperature setting by the knob 53.The operator then adjusts the timer 55 by the knob 54 to the desiredrate of rise of temperature for the system 20 and adjusts the hold timer50 by the knob 49 to the desired hold period of the final temperaturewhereby once the power switch 56 is in the on position and the startbutton 61 is actuated, the controller 20 will cause the valve 23 tooperate the heat exchanger 21 in such a manner that once the initialoutput temperature effect of the heat exchanger 21 reaches the starttemperature of the set point index 52, the set point index 52 will bemoved by the timer 55 in a manner hereinafter described at a set rate ofrise to cause the heat exchanger 21 to have the output temperatureeffect thereof rise at a certain rate until the output temperatureeffect reaches the setting of the high limit index 47 at which time thetimer motor 50 will then begin to operate and hold the outputtemperature effect of the heat exchanger 21 at the output temperatureeffect setting of the high limit index 47 for the length of time thatthe hold timer 50 has been set by the knob 49. At the lapse of such holdtime period, the control circuit 51 will then automatically shut downthe system 22.

It is well known that such time scheduled controlled systems can beutilized for various purposes, such as maintaining a dye bath fortextiles and the like at the desired rate of rise in temperature andthen at the desired hold temperature thereof for a pre-selected timeperiod.

While one of the features of this invention is to pro vide improvedmeans for the controller 20 to cause the controller 20 to perform theaforementioned time schedule control of the system 22 and such means isprovided by the pen and bridge assembly 45 later to be described, it isbelieved necessary to further describe the system 22 and the circuit 51in order to fully understand the operation of the controller 20 whenutilizing the various features of this invention.

Accordingly, as illustrated in FIG. 13, the system 22 has the portionthereof disposed within the dash-dotted rectangle 68 physically disposedwithin the casing 41 of the controller 20 wherein the conduit 32 for thesupply pressure 33 has a branch conduit 69 leading therefrom in advanceof the restrictor 34 for supplying supply pressure to a conventionalamplifying pneumatic relay 70.

The amplifying pneumatic relay 70 is adapted to direct its outputpressure into a conduit 71 with such output pressure being proportionalto but an amplification of the signal pressure being received therebyfrom a conduit 72 interconnected to the conduit 32 downstream from therestrictor 34. Thus, the relay 70 senses and amplifies the pressure inthe line 32 downstream from the restrictor 34 which pressure is inrelation to the amount of opening or closing of the vent nozzle 31 bythe balance beam 29 so that such output pressure in line 71 and beingdirected by the conduit 73 not only to the chamber 27 of the pneumaticactuator 26 for the main steam valve 23, but also to the chamber 74 ofthe feedback bellows 36 is in relation to the amount of opening orclosing of the nozzle 31 by the balance beam 29. Thus, a movement of thebeam 29 away from the nozzle 31 by the process bellows 3S sensing atemperature effect of the bath greater than the particular setting ofthe set point index line 43 causes a corresponding drop in pressure inthe conduit 32 downstream from the restrictor 34 so that the amplifier70 has its output pressure 71 correspondingly decreased whereby thevalve member 25 moves closer to the valve seat 24 to decrease the outputtemperature effect of the heat exchanger 21. However, since the pressurein the chamber 74 of the feedback bellows 36 correspondingly decreases,the same tends to move the beam 29back toward the nozzle 31 to therebyincrease the pressure in the line 32 and, thus, to the relay 70 to causean increase in the output pressure 71 thereof to tend to open the valvemember 25 away from the valve seat 24 whereby the feedback arrangement36 tends to eliminate an overshooting of the control of the heatexchange 21 in a manner well known in the art. Thus, it is sufficient tostate that the controller for the system 22 is adapted to maintain theoutput temperature effect of the heat exchanger 21 at the starttemperature setting of the set point index 52 and maintain such outputtemperature effect at a rate of rise that the index 52 is being moved bythe rate of rise timer in a manner hereinafter described because theposition of the set point link 43 determines the temperature setting forthe proportional mechanism 30 at any one time in the operation ofthesystem 22 by the controller 20.

The conduit 32 downstream from the restrictor 34 of the system 22 isinterconnected by a conduit 75 to a vent nozzle 76 that is opened andclosed by a valve member 77 carried on a flapper armature 78 of the 15/1valve 64. The armature 78 is normally urged to an open position by aspring means 79 in FIG. 13 and an electrical coil 80, when energized, isadapted to attract and pull the armature 78 downwardly in opposition tothe force of the spring 79 and have the valve member 77 close the ventopening 76 as long as the coil 80 is energized. However, when the coil80 is de-energized, the spring means 79 moves the valve member 77 awayfrom the vent opening 76 to open the conduit 32 so that no pressurebuild-up can occur in the line 32 and, thus, in the output line 71 ofthe relay so that the main steam valve 23 will automatically close bythe force of the spring 28 whenever the vent nozzle 76 is in an openposition. Thus, it requires the energizing of the coil 80 to close thevent nozzle 76 in order to permit the main steam valve 23 to be operatedby the controller 20 in the manner previously described.

The E/P valve 64, while illustrated schematically in FIG. 13, isillustrated in detail in FIG. 12 and it can be seen that the vent nozzle76 thereof comprises a tubular member 81 passing through the center ofthe electrical coil 80 and the armature or flapper 78 when moved to theopen position by the spring 79 abuts against a stop arm 82 of anL-shaped frame member 83 that has one leg 84 thereof interconnected tothe tension spring 79 with the other end of the tension spring 79 beinginterconnected to the armature 78. Thus, when the coil 80 is energized,the armature 78 is pulled downwardly to close the upper end of the tube81 and permit a pressure build-up in the line and, thus, in the maincontrol line 32 for the reasons previously set forth.

As illustrated in FIG. 14, the coil for the E/P valve 64 is adapted tohave one side 81' thereof interconnected by a lead 82' to the selectorswitch 63 and the other side 83 thereof interconnected by a lead 84' tothe lead 60 ofthe circuit 51.

A chart drive motor 85 is adapted to have one side 86 thereofinterconnected to the power source lead L by a lead 87 and the otherside 88 thereof interconnected by a lead 89 to the power source lead Lso that whenever the controller 20 is plugged into a power source, suchas a conventional l 10 volt alternating current source, the chart 46' ofthe controller 20 is driven by the chart drive motor 85 at a continuousrate so that the ink pen 46 continuously records thereon the actualsensed output temperature effect of the process bath 21 even though thecontroller 20 is not operating the heat exchanger 21 and the main steamvalve 23 is disposed in its closed position. A pilot light 90 is placedacross the leads 59 60 by leads 91 and 92. Similarly, an end of cyclelight 93 is placed across the leads 59 and 60 by leads 94 and 95.However, the lead 94 has the normally closed relay contacts 50' thereinfor a purpose hereinafter described and the contact 67 for the selectorswitch 63 is interconnected by a lead 96 to the lead 94 intermediate themain lead 59 and relay contacts 50'. The contact 66 for the selectorswitch 63 is interconnected to the lead 59 by a lead 97.

A hold light 98 has one side 99 thereof interconnected to the lead 60 bya lead 100 while the other side 101 thereof is interconnected by a lead102 to a normally open contact 103 of a limit switch 104 which formspart of the pen and bridge assembly 45 later to be described.

A switch blade 105 of the switch 104 is interconnected to the lead 59and normally is disposed against a 7 contact 106 to electricallyinterconnect the lead 59 to a lead 107 that is interconnected to acontact 108 of a pneumatically operated switch 109. The switch 109 hasits switch arm 110 normally bridging the contact 108 with a contact 111as long as the pneumatic sensor 112 thereof senses that the outputpressure from the relay 70 to the pneumatically operated valve 23 doesnot exceed a full open pressure which in the system 22 is a pressureabove 15 psi. Since the control range for the output pressure from therelay 70 to the steam valve 23 is normally 3 to 15 psi, the switch 109is normally disposed in its closed position bridging the contacts 108and 111 unless the same senses a pressure above 15 psi.

The contact 111 is interconnected by a lead 113 to one side 114 of arate of rise light 115 while the other side 116 thereof isinterconnected by lead 117 to the lead 60. A drive motor 118 for movingthe set point index 52 in a manner hereinafter set forth has one side119 thereof interconnected by a lead 120 to the lead 60 and the otherside 121 thereof interconnected by a lead 122 to normally open relaycontacts 55' of the rate of rise timer motor 55. The rate of rise timermotor 55 opens and closes the contacts 55' on a percentage of time basisduring the running of the rate of rise timer motor 55 so that theclosing percentage of the contacts 55 may be varied by the setting ofthe rate of rise adjustment knob 54 on the controller 20 whereby thetimer 55 will operate the drive motor 118 in an on and off manner tomove the set point index 52 at the desired rate of rise thereof as willbe apparent hereinafter.

The rate of rise timer motor 55 has one side 123 thereof interconnectedto the lead 60 by a lead 124 while the other side 125 thereof isinterconnected to the lead 113 by a lead 126 that is also connected toone side of the normally open relay contacts 55 of the timer motor 55.The hold timer motor 50 has one side 127 interconnected by a lead 128 tothe lead 60 while the other side 129 thereof is interconnected by a lead130 to the lead 102.

As illustrated in FIGS. 3-8, the bridge and pen assembly 45 includes apair of bridge members or frame plates 131 and 132 for mounting thebridge and pen assembly 45 in the controller casing 41, the upper bridgemember 131 being supported on the lower bridge member 132 by a pluralityof posts 133. A cylindrical pin 134 is carried by the bridge plates 132and 131 and does not rotate relative thereto as the same is held inplace by set screws such as at 135, FIG. 4A. A bushing 136 is carried bythe upper bridge member 131 and has the pin 134 passing therethroughbeyond the top beveled surface 137 thereof.

The pen 46, the high limit index 47 and the set point index 52respectively have U-shaped parts 138, 139 and 140 with the upper arms141, 142 and 143 thereof provided with openings 144, 145 and 146 passingtherethrough and receiving the portion of the pin 134 that projectsbeyond the bushing 136, as illustrated in FIG. 4A. Spacers 147 and 148are respectively disposed on opposite sides of the intermediate arm 142of the high limit index 47. The arms 141-143 are held in the stackedrelation illustrated in FIGS. 4 and 4A by a retaining ring 149 and thepin 134 is adjusted such that a gap of approximately 0.010 of an inchexists between the pen arm 141 and the retaining ring 149 when all ofthe leverage members 141-143 are in the downward position, asillustrated in FIG. 4, whereby sufficient end play is provided toprevent any possibility of binding of the leverage members 141-143 intheir rotation on the pin 134.

The U-shaped member 138 for the pen 46 has the lower arm 150 thereofprovided with an opening 151 passing therethrough and receiving the pin134 inter mediate the bridge members 131 and 132, as illustrated in FIG.7. A link 152 also has an opening 153 passing therethrough and receivingthe pin 134 with the link 152 being fastened to the arm 150 of the penassembly 46 so that movement of the link 152 by the interconnectedprocess pen, link 44 will cause the pen 46 to pivot or rotate on the pin134 and mark across the chart 46 as the chart 46' is being driven by itsdrive motor 85.

The lower legs 154 and 155 of the U-members 139 and 140 for the indexes47 and 52 respectively receive the pin 134 through suitable openingstherein with such arms 154 and 155 respectively being riveted asillustrated to gear-cam members 156 and 157 likewise disposed forrotation on the pin 134 at openings 158 and 159 passing respectivelytherethrough.

The gear-cams 156 and 157 can be produced from like stampings or can beslightly modified from each as will be apparent hereinafter. However,such gear-cam members 156 and 157 respectively rotate with the indexes47 and 52 on the pin 134 so that the gear-cam members 156 and 157comprise alignable members for the indexes 47 and 52 as will be apparenthereinafter.

As illustrated in FIG. 5, the cam-gear member 156 for the high limitindex 47 has a part 160 of the outer periphery 161 thereof formed withgear teeth thereon which are adapted to be disposed in meshingengagement with a pinion gear 161 fastened by a set screw 162, FIG. 8,to a shaft member 163 rotatably carried by the bridge members 131 and132 and having an extension 164 passing through the upper bridge member131 and being fastened by a set screw 165 to a knob member 166 adaptedto rotate the shaft 163 in a manner hereinafter set forth.

Similarly, the cam-gear member 157 for the index 52 has a portion 167 ofthe outer periphery 168 thereof provided with gear teeth disposed inmeshing relation with the gear teeth of a pinion gear 169 fastened by aset screw 170 to a shaft 171 mounted for rotation between the bridgeplates 131 and 132 and likewise having a knob member 172 on the upperend thereof for adjusting the rotational position of the shaft 171 in amanner hereinafter described. However, the shaft 171 is also coupled bya coupling member 173 to an output shaft 174 of the set point drivemotor 118 carried on the lower bridge member 132 as illustrated wherebywhen the drive motor 118 is energized in the circuit 51 of FIG. 14, thegeared down output shaft 174 thereof rotates the shaft 171 and, thus,the pinion gear 169 to drive the cam-gear 157 about the pin 134 and,thus, rotate the index 52 about the pin 134 in unison therewith.

The arm 154 of the U member 139 for the high limit index 47 extendsbeyond the cam gear member 156 thereof and carries the limit switch 104in fixed position thereon, the limit switch 104 having an operatingplunger 105 which when in its out condition makes contact with thecontact 106 of the circuit 51 and when caused to move inwardly by a camfollower 175 thereof being forced out of a recessed cam part 176 of theouter periphery 161 of the cam gear member 156, as illustrated in FIG.5, causes the switch blade 105 of FIG. 14 to bemoved out of contact withthe contact 106 and placed into contact with the contact 103 for apurpose hereinafter described.

The cam follower arrangement 175 is so constructed and arranged that thesame does not ride on the outer periphery 161' of the cam gear member156 for the high limit index 47 but is movable into the recessed camarea 176 thereof. However, the cam follower 175 does ride in theelongated cam portion 177 of the gear member 157 when the same isrotating relative thereto.

The cam wheels or members 156 and 157 are so constructed and arrangedthat the cam follower 175 of the cam assembly 175 will be midway betweenthe highest and lowest level of its cammed position as it rides out ofthe recess 177 of the member 157 toward the outer periphery 168 thereofwhen the indexes 47 and 52 are at their point of coincidence so that thesnap acting switch 104 can be made to trip at the exact point ofcoincidence of the indexes 47 and 52. Further, both indexes 47 and 52are capable of causing the switch 104 to trip as the result of themovement of the cam follower assembly 175 being driven toward the switch104 by the ramping action of the cam gear 157 of the set point index 52as it rotates clockwise in FIG. 6 and the point of switch actuation willbe the alignment of the assemblies 47 and 52 to force the cam follower175' out of the cam 176 of the gear cam 156 for the high limit index 47and tend to ride on the high portion of the outer periphery 161' of thegear cam 157 of the set point index 52.

Therefore, it can be seen that when the high limit index 47 has been setto a desired position thereof by the rotation of the pinion gear 161rotating the cam gear member 156 and, thus, the high limit index 47, theswitch 104 is being positioned therewith so that the set point index 52when driven by the motor 118 into a position of coincidence with thehigh limit index 47 will have its cam 157 operate the snap switch 104 tomove the contact from the contact 106 to the contact 103 for a purposehereinafter described to start the hold time of the control circuit 51.

As previously stated, movement of the set point index 52 by the motor118 causes the set point link 43 that is interconnected to the set pointindex 47 to adjust the proportional mechanism 30 to cause the outputtemperature effect of the heat exchanger 21 to follow the new setting ofthe index 52 as the same is being driven toward the high limit settingof the index 47 at which point the indexes 52 and 47 will be incoincidence so that the cam-gear 157 can operate the limit switch 104from the position illustrated in FIG. 14 to open the contact 106 andclose the contact 103 for a purpose hereinafter described.

In order to initially adjust the positions of the shafts 163 and 171 torespectively set the high limit position for the index 47 and thestarting position for the set point index 52, the adjustment knobs 48and 53 on the cover 42 of the controller casing 41 are formed in a likemanner to respectively control the inside knobs 166 and 172 on theshafts 163 and 171.

Since such structure is identical, only one such structure isillustrated in FIGS. 9-11 and, since the same comprises the adjustingknob 48 for the high limit index 47, it is to be understood that likestructure is provided for the knob 53 to adjust the initial position ofthe set point index 52.

As illustrated in FIG. 9, the cover 42 has a sleeve 178 passingtherethrough and receiving a cylindrical portion 179 ofa rectangularlycross sectioned rod 180 that has the non-cylindrical portion thereofextending below the sleeve 178 and passing through a rectangular opening181 in a plate 182 having a pair of outwardly directed, diametricallydisposed tangs 183 adapted to respectively be received in diametricallyopposed notches 184 formed through the knob 166 for the shaft 163 whilethe remainder of the plate 182 is received in a central recess 185 inthe knob 166, as illustrated in FIG. 9. The plate 182 is held on the rod180 by a threaded fastening member 186 and is urged against the head 187of the threaded fastening member 186 by a compression spring 188disposed between the sleeve 178 and the plate 182, as illustrated inFIG. 9, whereby the plate 182 is adapted to move up and down on the rod180 in opposition to the force of the compression spring 188.

As illustrated in FIG. 9, the adjustment knob 48 is fastened to thecylindrical portion 179 of the rod 180 by a set screw 189 so that theknob 48 will rotate in unison with the rod 180.

After the cover 42 has been in the open position illustrated in FIG. 2and, thereafter, is moved to its closed position as illustrated in FIG.1 and locked in such position by suitable locking means 190, FIG. 1,should the tangs 183 ofa plate 182 for a particular adjusting knob 48 or53 be out of register with the slots 184 in the cooperating knob 166 or172, as illustrated in FIG. 10, the tangs 183 merely engage against theupper surface 191, as illustrated in FIG. 10, permitting the plate 182to telescope on the rod 180 in opposition to the force of thecompression spring 188 in order to permit the cover 42 to move to itsfully closed position. Thereafter, the operator merely rotates theparticular knob 48 or 53 at least a quarter of a turn in any directionand the tangs 183 of the plate 182 will snap into the slots 184 underthe force of the compression spring 188 in the manner illustrated inFIG. 11 as the same come into alignment with the notches 184 so that theinterconnection between the outer knob 48 or 53 on the cover 42 to therespective inner knob 166 or 172 is a simple operation merely thereafterrequiring rotation of the knobs 48 and 53 lock the tangs 183 in place.Thereafter, the knobs 48 and 53 will respectively adjust the indexes 47and 52 in the manner previously described to set the same at the desiredbeginning positions thereof for a controlled operation for the system 22as now to be described.

When the operator presses the power button 56 for the controller 20 tomove the same to an on position thereof, the switches 57 and 58 aremoved to their closed positions to interconnect the fused power sourcelines L and L to the leads 59 and 60 whereby the pilot light 90 is nowturned on as the same is placed across the power source leads L and L Ifthe selector switch 63 is in its manual position so as to be away fromthe contact 66 and against the contact 67, the coil 80 of the E/P valve64 will be energized to close the valve member 77 against the ventnozzle opening 76 of the tubular member 81 whereby output pressure isprovided from the relay 70 to the conduit 73 for controlling the mainsteam valve 23.

However, if an automatic operation for the controller 20 is provided,the selector switch 63 is disposed in the automatic position illustratedin FIG. 1 whereby the switch 63 is closing against the contact 66 sothat current cannot be directed to the solenoid until the normallyopened relay contact 50" are closed. Since the contacts 50" are in theopen position when the hold timer motor 50 is not timing and thecontacts 50 thereof are in the closed position, as illustrated in FIG.14, as is true before the beginning of each process run, the end cyclelight 93 will be initially on as the same is energized through normallyclosed contacts 50.

The operator then sets the high limit index 47 through the knob 48 tothe desired temperature at which the set point index 52 is to stop atits end of travel. The set point index 52 is then positioned by the knob53 to the desired initial temperature setting that the controller 20 isto control the heat exchanger 21: Thus, the limit switch 104 is moved toa certain position when the high limit index 47 is so moved to a setposition and the cam gear 157 for the set point index 52 is moved to acertain beginning position thereof so that the cam follower 175 is inits outermost position whereby the limit switch 104 has its bladeagainst the contact 106, as illustrated in FIG. 14.

The operator then adjusts the rate of rise adjustment knob 54 to thedesired rate of rise temperature that the set point index 52 is tocontrol the heat exchange 21 in reaching the high limit temperaturesetting of the high limit index 47. The operator then sets the holdtimer knob 49 to the desired length of time that the high limittemperature for the heat exchanger 21 is to be maintained by thecontroller 20.

After all of the aforementioned selections have been made, the operatorthen depresses the start button 61 j If the selector switch 63 is in theauto position illustrated in FIG. 14, the coil 80 of the E/P valve 64will now be energized since the contacts 50" are closed allowing thesteam valve 23 to open to begin to heat the desired process material bythe heat exchanger 21. As long as the pressure operated switch 109 isclosed, electrical current is applied to the rate of rise timer motor55, rate of rise light 115 and set point drive motor 118. However, therunning time of set point drive motor 118 is regulated by the closinginterval of the contacts 55 which is a function of the percentage of theoperation of the timer 55 whereby the average rate at which the setpoint index 52 is driven by the timer motor 118 up scale by the motor 118 toward the high limit index 47 is determined by the setting of theknob 54 for the rate of rise selection.

If the pneumatically operated switch 109 should open, the rate of risetimer 55 and set point drive motor 118 cannot run and the set pointindex 52 will not rise. The pressure operated switch 109 is usuallycalibrated to open only at output pressures above psi and the controlrange of output pressure for the controller 20 is normally 3 to 15 psi.On the reverse acting steam valve 23, the output pressure increases inthe chamber 27 when more heat is demanded and most steam valves are wideopen at pressures exceeding 15 psi. When the process is incapable ofrising at the rate of movement of the set point index 52, the outputpressure will exceed 15 psi and will cause the pressure operated switch109 to open. By appropriate choice of proportional band setting and/orpressure switch setting, the actual permissible process lag may bevaried according to need.

The rise of the set point index 52 by the timer motor 118 will continuein the manner previously described to cause the output temperatureeffect of the heat exchanger 21 to continuously increase until theswitch 104 is tripped by the alignable members 157 and 156 for theindexes 52 and 47 being coincident as previously described so that theblade 105 of the switch 104 now moves away from the contact 106 and isplaced against the contact 103. Such position of the switch 104completely disconnects the set point drive motor 118 and timer 55 fromacross the power source L, and L to terminate further up scale movementof the set point index 52 and, thus, increase of output temperatureeffect of the heat exchanger 21.

At this time, the power source 61 and 62 is now applied to the holdlight 98 and to the hold timer motor 50 whereby the timer motor 50 willcontinue to run for the time period as set by the knob 49 so that theoutput temperature effect of the heat exchanger 21 is maintained at thehigh limit temperature setting of the high limit index 47 for this timedperiod as the set point index 52 is now stationary at this hightemperature setting so as to maintain the controller at the hightemperature setting through the now stationary link 43 thereof.

When the hold timer 50 runs down, the hold timer contacts 50 and 50 arereversed so that the contacts 50 now close and the contacts 50" openwhereby the end of cycle light 93 is turned on, the hold light 98 goesoff and the timer motor 50 stops running.

If the selector switch 63 is in the automatic position as illustrated inFIG. 14, the E/P valve coil 80 is now de-energized since the contacts 50are open and the controller output pressure falls to zero through themovement of the valve member 77 away from the valve nozzle 76 of the E/Pvalve 64 and the heat exchanger 21 will now return the process to a shutdown condition thereof.

However, if the selector switch 63 was in a manual position so that thesame was against the contact 67 rather than against the contact 66, thecoil 80 for the lE/P valve will remain energized even though the timermotor 50 is turned off and the process will not shut down whereby shutdown must then be affected by the use of the power switch 56 beingturned to the off position at the discretion of the operator.

Therefore, it can be seen that a unique means is provided for providingan automatic cycle of operation of the controller 20 to control thesystem 22 in such a manner that the rise of the set point index 52 froman initial setting thereof to a high temperature setting coincident withthe setting of the high limit index 47 will cause the heat exchanger 21to be held at such high limit output temperature effect for a timedperiod so that when the timed period has elapsed, an automatic shut downof the process will be completed. Also, it can be seen that improvedparts for such a time schedule controller have been provided.

While the form of the invention now preferred has been disclosed asrequired by the patent statutes, other forms may be utilized all comingwithin the scope of the appended claims.

What is claimed is:

1. In a time schedule controller wherein a high limit index is adaptedto be set at a desired condition and the rate of rise of a set pointindex is adapted to be selected so that the controller will tend tomaintain an output effect of a controlled device at the selected rate ofrise of said set point index until the output effect reaches said setcondition of said high limit index, the improvement wherein said highlimit index and said set point index respectively have means movabletherewith and alignablein relation to each other only when said setpoint index reaches the setting of said set high limit index, andactuator means for terminating the operation of said set point index inthe rate of rise thereof when said actuator means is actuated, saidalignable means of said high limit index and said set point index beingoperatively associated with said actuator means to actuate the same onlywhen said alignable means are in said aligned relation thereof.

2. In a time schedule controller as set forth in claim 1, the furtherimprovement wherein said alignable means of one of said indexes comprisea movable cam movable in unison with its respective index.

3. ln a time schedule controller as set forth in claim 2, the furtherimprovement wherein said indexes are respectively rotatable about afixed axis, said .cam also being rotatable about a fixed axis.

4. In a time schedule controller as set forth in claim 3, the furtherimprovement wherein the other of said indexes carries said actuatorwhereby said actuator comprises said alignable means thereof.

5. In a time schedule controller as set forth in claim 4, the furtherimprovement wherein said actuator means comprises an electrical switch.

6. In a time schedule controller as set forth in claim 1, the furtherimprovement wherein said controller has a pair of adjusting means forrespectively adjusting the settings of said indexes, said adjustingmeans being respectively and operatively interconnected to saidalignable means for adjusting the respective indexes.

7. In a time schedule controller as set forth in claim 6, the furtherimprovement wherein said adjusting means each comprises a gear member,said alignable means each comprising a gear part disposed in meshingrelation with its respective gear member.

8. In a time schedule controller as set forth in claim 1, the furtherimprovement wherein one of said alignable means comprises said actuatormeans and the other of said alignable means actuating said actuatormeans

1. In a time schedule controller wherein a high limit index is adaptedto be set at a desired condition and the rate of rise of a set pointindex is adapted to be selected so that the controller will tend tomaintain an output effect of a controlled device at the selected rate ofrise of said set point index until the output effect reaches said setcondition of said high limit index, the improvement wherein said highlimit index and said set point index respectively have means movabletherewith and alignable in relation to each other only when said setpoint index reaches the setting of said set high limit index, andactuator means for terminating the operation of said set point index inthe rate of rise thereof when said actuator means is actuated, saidalignable means of said high limit index and said set point index beingoperatively associated with said actuator means to actuate the same onlywhen said alignable means are in said aligned relation thereof.
 2. In atime schedule controller as set forth in claim 1, the furtherimprovement wherein said alignable means of one of said indexes comprisea movable cam movable in unison with its respective index.
 3. In a timeschedule controller as set forth in claim 2, the further improvementwherein said indexes are respectively rotatable about a fixed axis, saidcam also being rotatable about a fixed axis.
 4. In a time schedulecontroller as set forth in claim 3, the further improvement wherein theother of said indexes carries said actuator whereby said actuatorcomprises said alignable means thereof.
 5. In a time schedule controlleras set forth in claim 4, the further improvement wherein said actuatormeans comprises an electrical switch.
 6. In a time schedule controlleras set forth in claim 1, the further improvemenT wherein said controllerhas a pair of adjusting means for respectively adjusting the settings ofsaid indexes, said adjusting means being respectively and operativelyinterconnected to said alignable means for adjusting the respectiveindexes.
 7. In a time schedule controller as set forth in claim 6, thefurther improvement wherein said adjusting means each comprises a gearmember, said alignable means each comprising a gear part disposed inmeshing relation with its respective gear member.
 8. In a time schedulecontroller as set forth in claim 1, the further improvement wherein oneof said alignable means comprises said actuator means and the other ofsaid alignable means actuating said actuator means when alignedtherewith.
 9. In a time schedule controller as set forth in claim 8, thefurther improvement wherein said actuator means comprises an electricalswitch having an operating plunger, said other alignable means acting onsaid plunger to move the same when in alignment with said one alignablemeans.
 10. In a time schedule controller as set forth in claim 9, thefurther improvement wherein said other alignable means comprises a cammovable with its respective index and acting on said plunger of saidswitch.